Redone RMG template serialization using JSON serializer, added tests

include/vstd/ContainerUtils.h

@@ -0,0 +1,28 @@
+/*
+ * ContainerUtils.h, part of VCMI engine
+ *
+ * Authors: listed in file AUTHORS in main folder
+ *
+ * License: GNU General Public License v2.0 or later
+ * Full text of license available in license.txt file, in main folder
+ *
+ */
+
+#pragma once
+
+namespace vstd
+{
+	template<typename K, typename V>
+	std::map<V, K> invertMap(const std::map<K, V> & m)
+	{
+		std::map<V,K> other;
+		std::transform(m.cbegin(), m.cend(), std::inserter(other, other.begin()), [](const std::pair<K, V> & p)
+		{
+			return std::make_pair(p.second, p.first);
+		});
+		return other;
+	}
+}
+
+
+